Sonja Wiersinga (1972) has more than 20 years experience as an Office Manager and Personal Assistant.

She is the Office Manager of Leaderman N.V. and Leaderman Luxembourg S.A. and Personal Assistant to Stan Miller.

From March 2008 till December 2010 Sonja was Personal Assistant and coordinator of Investor Relations (IR) of Royal KPN NV. She was responsible for the coordination of all logistic processes of Roadshows and Seminars of the IR-team and Board of Management and the communication and meetings with the Analysts, Bankers and Investors of Royal KPN NV.

Since July 2003 Sonja served as Personal Assistant of the CFO of Royal KPN NV and Secretary of the Management Team Meetings.

From 2000 to 2003, she was the Personal Assistant of the CEO of KPN Mobile The Netherlands and Secretary of the Exco Meetings.

Prior to joining KPN, she was Office Manager and Personal Assistant in three law firms for 8 years.

Sonja has also been a successful Manager in hospitality services for many years.